1. Field of the Invention
This invention relates to an r.f. signal processing apparatus, and in particular to a capacitorless DC bias line module used in an r.f. signal processing apparatus.
2. Description of the Prior Art
DC bias line modules are generally employed with r.f. (radio frequency) signal processing equipment, such as microwave amplifiers, which is used to provide gain. Also DC bias is employed to compensate for temperature variations in an amplifier which is subject to temperature variations. In the past, DC bus lines or DC bias lines incorporated capacitors to prevent the DC bias lines from resonating by providing r.f. "shorts" periodically along the bus lines. The capacitors were spaced at distances not greater than one-half wave length at the highest operating frequency of the apparatus, as illustrated in FIG. 1. Each capacitor C is shown as having one plate connected to a junction between adjacent DC bias lines 10a . . . 10n and the other plate to a reference potential, such as ground. However, it is well known that capacitors are subject to failure which results in degraded reliability. Also, capacitors used with DC bus lines are relatively large and occupy too much space for systems that require compactness of design.